The subject matter of this specification relates generally to advertising.
Online video is a growing medium. The popularity of online video services reflects this growth. Advertisers see online video as another way to reach their customers. Many advertisers are interested in maximizing the number of actions (e.g., impressions and/or click-throughs) for their advertisements. To achieve this, advertisers make efforts to place advertisements with content that is relevant to their advertisements. For example, an advertiser can target its car advertisements to a website about cars.